Characterization of Copper tolerant (Cur) strain of Nostoc calcicola Breb revealed its ability to grow at 70μM Cu being 60μM Cu is saturating concentration for sensitive (Cus) strain. The overall pattern indicated the acquisition of metal tolerance in the former. In Cu uptake comparisons, the Cur strain showed only 26% less cellular metal buildup (72.15 n mol Cu mg-1 protein) at 60 min compared to Cus (96.89 n mol Cu mg-1 protein). The Cur strain exhibited the lower level of Phosphate uptake, Ca2+ and Mg2+ dependent ATPase activities, 14CO2-incorporation, Nitrogenase and Glutamine synthetase activities.